Creamy Leek and Mushroom Bake

Ingredients

• 5 Tablespoons butter (divided)
• 1 stalk leek ((white and light green parts only), halved lengthwise and then sliced crosswise)
• 1/2 teaspoon each salt and pepper
• 24 oz cremini and/or button mushrooms (sliced (three 8oz trays))
• 1/3 cup all-purpose flour
• 1 1/4 cups chicken broth (or sub vegetable broth to keep it vegetarian)
• 1/2 cup whipping cream 35%
• 2 Tablespoons grainy Dijon mustard
• 1/2 cup chopped fresh parsley
• 1 Tablespoon chopped fresh thyme
• 4 teaspoons lemon juice
• 2 cups fresh bread crumbs (slightly stale bread, processed in food processor)
• 3/4 cup grated Gruyère cheese
• 2 Tablespoons butter (melted)
• 2 Tablespoons chopped fresh parsley

Instructions

1. 1

   In a large skillet, melt 1 Tbsp. of the butter over medium heat. Cook leeks and half each of the salt and pepper, stirring often, until leeks are softened, about 6 minutes. Remove to bowl and set aside.

2. 2

   In the same skillet, melt the remaining 3 Tbsp. butter over medium heat. Cook mushrooms with the remaining salt and pepper, stirring occasionally, until mushrooms are just tender and have released their juices, 5 to 8 minutes. Sprinkle with flour and cook, stirring, until light golden, about 2 minutes. Return the leeks to the pan.

3. 3

   Whisk in broth, cream and mustard until smooth. Cook, whisking, until thickened, 3 to 5 minutes. Stir in parsley, thyme and lemon juice. Spoon into shallow 8-cup casserole dish. (Make-ahead: Let mushrooms cool to room temperature, then cover and refrigerate for up to 24 hours. To reheat, cover with foil and bake in 375° F. oven until hot and bubbly, 40-50 minutes. Uncover and continue with recipe. You can also mix together the crumbs and cheese of the crumb topping and refrigerate ahead. When ready to broil, stir in parsley and melted butter.)

4. 4

   Gruyère Crumb Topping: In bowl, stir together bread crumbs, Gruyère cheese, butter and parsley. Sprinkle over mushroom mixture. Broil until topping is golden, 2 to 4 minutes.